程序头部注释开始
* 程序的版权和版本声明部分
* Copyright (c) 2011, 烟台大学计算机学院学生
* All rights reserved.
* 文件名称: 复数类的改进
* 作 者: 郭广建
* 完成日期: 2012年 4 月 03 日
* 版 本 号: 1.0
题目介绍:
【任务3】阅读P314的例10.1(电子版的在平台上见txt文件)。该例实现了一个复数类,但是美中不足的是,复数类的实部和虚部都固定是double型的。可以通过模板类的技术手段,设计Complex,使实部和虚部的类型为定义对象时用的实际类型。
(1)要求类成员函数在类外定义。
(2)在此基础上,再实现减法、乘法和除法
你可以使用的main()函数如下。
int main( )
{ Complex<int> c1(3,4),c2(5,-10),c3;
c3=c1.complex_add(c2);
cout<<"c1+c2=";
c3.display( );
Complex<double> c4(3.1,4.4),c5(5.34,-10.21),c6;
c6=c4.complex_add(c5);
cout<<"c4+c5=";
c6.display( );
system("pause");
return 0;
}
附:例10.1的代码
#include <iostream>
using namespace std;
class Complex
{
public:
Complex( ){real=0;imag=0;}
Complex(double r,double i){real=r;imag=i;}
Complex complex_add(Complex &c2);
void display( );
private:
double real;
double imag;
};
Complex Complex::complex_add(Complex &c2)
{
Complex c;
c.real=real+c2.real;
c.imag=imag+c2.imag;
return c;
}
void Complex::display( )
{
cout<<"("<<real<<","<<imag<<"i)"<<endl;
}
int main( )
{
Complex c1(3,4),c2(5,-10),c3;
c3=c1.complex_add(c2);
cout<<"c1="; c1.display( );
cout<<"c2="; c2.display( );
cout<<"c1+c2="; c3.display( );
return 0;
}
源程序:
#include<iostream>
using namespace std;
template<class comstyle>
class Complex
{
public:
Complex( ){real = 0; imag = 0;}
Complex(comstyle r,comstyle i){real = r; imag = i;}
Complex complex_add(Complex &c2);
Complex complex_subtract(Complex &c2);
Complex complex_multiply(Complex &c2);
Complex complex_divide(Complex &c2);
void display( );
private:
comstyle real;
comstyle imag;
};
template<class comstyle>
Complex<comstyle> Complex<comstyle>::complex_add(Complex<comstyle> &c2) //加法定义
{
Complex<comstyle> c;
c.real = real + c2. real;
c.imag = imag + c2. imag;
return c;
}
template<class comstyle>
Complex<comstyle> Complex<comstyle>::complex_subtract(Complex<comstyle> &c2) //减法定义
{
Complex<comstyle> c;
c.real = real - c2. real;
c.imag = imag - c2. imag;
return c;
}
template<class comstyle>
Complex<comstyle> Complex<comstyle>::complex_multiply(Complex<comstyle> &c2) //乘法定义
{
Complex<comstyle> c;
c.real = real * c2.real - imag * c2.imag ;
c.imag = real * c2.imag + imag * c2.real ;
return c;
}
template<class comstyle>
Complex<comstyle> Complex<comstyle>::complex_divide(Complex<comstyle> &c2) //除法定义
{
Complex<comstyle> c;
c.real = (real * c2.real + imag * c2.imag) / (c2 .real * c2.real + c2.imag * c2.imag);
c.imag = (imag * c2.real - real * c2.imag) / (c2 .real * c2.real + c2.imag * c2.imag);
return c;
}
template<class comstyle>
void Complex<comstyle>::display( )
{
cout<<"("<<real<<","<<imag<<")"<<endl;
}
int main( )
{ Complex<int> c1(3,4), c2(5,-10), c3;
c3 = c1.complex_add(c2);
cout << "c1+c2 =";
c3.display( );
c3 = c1.complex_subtract(c2);
cout << "c1-c2 =";
c3.display( );
c3 = c1.complex_multiply(c2);
cout << "c1*c2 =";
c3.display( );
c3 = c1.complex_divide(c2);
cout << "c1/c2 =";
c3.display( );
Complex<double> c4(3.1,4.4), c5(5.34,-10.21), c6;
c6 = c4.complex_add(c5);
cout << "c4+c5 =";
c6.display( );
c6 = c4.complex_subtract(c5);
cout << "c4-c5 =";
c6.display( );
c6 = c4.complex_multiply(c5);
cout << "c4*c5 =";
c6.display( );
c6 = c4.complex_divide(c5);
cout << "c4/c5 =";
c6.display( );
system("pause");
return 0;
}
运行结果:
经验积累:
1).类模板可以避免函数的重载的定义和运用的麻烦
2).但是在类中成员函数定义之前应该注意不能忘掉 “template<class comstyle>”
3).并没有一劳永逸的解决方法,一方面简单的同时,在某些方面肯定有很多注意点,所以在应用时要慎重!